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Exception when forwarding request to servlet in Java web application

I have a problem and I don't know how to solve it.
My web application MyApp is a Maven web application project (Java 8 and Java EE 5). To run an updated version as test instance on the same server, I changed the Context Path of the application from MyApp to MyAppTest. As servlet container, I'm using Tomcat 8.
The MyApp instance is working as expected. However the MyAppTest instance is throwing an exception when forwarding the request to one of my servlets. Even if MyApp and MyAppTest are identical except the context path, this exception occurs. The Servlets are mapped via Guice's ServletModule.
Message:
java.lang.StringIndexOutOfBoundsException: String index out of range: -4
StackTrace:
java.lang.String.substring(Unknown Source)
com.google.inject.servlet.ServletDefinition$2.getPathInfo(ServletDefinition.java:212)
org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:376)
org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318)
myapp.base.MainEntryServlet.service(MainEntryServlet.java:49)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
com.google.inject.servlet.ServletDefinition.doServiceImpl(ServletDefinition.java:286)
com.google.inject.servlet.ServletDefinition.doService(ServletDefinition.java:276)
com.google.inject.servlet.ManagedServletPipeline$1.doServiceImpl(ManagedServletPipeline.java:154)
com.google.inject.servlet.ManagedServletPipeline$1.forward(ManagedServletPipeline.java:140)
myapp.auth.LogoutServlet.service(LogoutServlet.java:57)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
com.google.inject.servlet.ServletDefinition.doServiceImpl(ServletDefinition.java:286)
com.google.inject.servlet.ServletDefinition.doService(ServletDefinition.java:276)
com.google.inject.servlet.ServletDefinition.service(ServletDefinition.java:181)
com.google.inject.servlet.ManagedServletPipeline.service(ManagedServletPipeline.java:91)
com.google.inject.servlet.FilterChainInvocation.doFilter(FilterChainInvocation.java:85)
com.google.inject.servlet.ManagedFilterPipeline.dispatch(ManagedFilterPipeline.java:120)
com.google.inject.servlet.GuiceFilter.doFilter(GuiceFilter.java:135)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
org.apache.coyote.ajp.AbstractAjpProcessor.process(AbstractAjpProcessor.java:873)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:670)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Unknown Source)
The Servlet forwarding the Request does this:
RequestDispatcher dispatcher = request.getRequestDispatcher("/index.jsp");
if (!response.isCommitted()) {
dispatcher.forward(request, response);
}
The URL index.jsp is mapped to another Servlet. It forwards the request to a JSP:
request.getRequestDispatcher("/theme/index.jsp").forward(request, response);
There the exception occurs. Some other JSPs are included into the index.jsp like this:
<jsp:include flush="true" page="menu.jsp"/>
The menu.jsp is located in the same folder as the index.jsp.
As mentioned before, everything works fine as long as the Context path is MyApp. When changed to MyAppTest the exception occurs. It must have something to do with the Context path itself. When changing the Path to MyAppTest, the exception message is "String index out of range: -4". When I change the Path to MyAppTesting, the exception message changes to "String index out of range: -7".
To solve this I tried the following:
Changing the Context path and the docBase to MyAppTest in the context.xml of the project.
Changing the Artifact ID of the project to MyAppTest.
Changing the Project Name to MyAppTest.
Nothing worked. And I don't know what causes the exeption: Maven, Tomcat or Guice.

Running Hbase with Java Servlets

I wrote a Hbase Java basic code that works fine with Java.
public class HBaseTest {
public static String newFunc() throws IOException {
// Instantiating configuration class
Configuration config = HBaseConfiguration.create();
Connection connection = ConnectionFactory.createConnection(config);
Table table = connection.getTable(TableName.valueOf("customer"));
Get g = new Get(Bytes.toBytes("jsmith"));
Result result = table.get(g);
// Reading values from Result class object
byte[] value = result.getValue(Bytes.toBytes("addr"), Bytes.toBytes("city"));
return Bytes.toString(value);
}
}
So I decided to use this code and Hbase as a part of my web application development and so I opened a new Dynamic Web Project in Eclipse Java EE IDE and added this file, changed the name of function and called it from one of the servlets. I also added the required jar files.
But I am stuck with the following error:
java.lang.ClassNotFoundException: org.apache.hadoop.hbase.HBaseConfiguration
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1332)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1166)
at HBaseTest.newFunc(HBaseTest.java:18)
at BakwasServlet.doGet(BakwasServlet.java:16)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1099)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:670)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
This error is frustrating me now. Has anyone encountered such a case before or can anyone help me on this? I don't have hbase_home variable set up. I didn't need it for the java code as well.
Thanks in advance!

Where have you added the HBase JAR file? It should be in the WEB-INF/lib folder of your web application (or in the server's lib folder, but it's better to keep it within the app).

Using JNI so files on a dynamic web project(Apache Tomcat Server)

I am making a dynamic web project, which requires to use an external jar file. That jar uses several JNI so files. Now I have the jar and all the required so files. I have added the jar to the java build path, but I am not sure how to introduce the so files to the tomcat server.
I tried adding path to the so file as "LD_LIBRARY_PATH":
(Properties->Run/Debug Settings->edit->Environment->Select) and also
adding the path to "java.library.path"(Run
As->RunConfigurations->Tomcat v8 Server->Arguments->VM arguments)
flag.
Still it is not working, I am getting below error, whenever the my code is trying to access functions/classes from the above mentioned jar:
SEVERE: Servlet.service() for servlet [org.iotivity.simulator.agent.LaunchSimulator] in context with path
[/SimulatorAgent] threw exception [Servlet execution threw an
exception] with root cause java.lang.ClassNotFoundException:
org.oic.simulator.server.SimulatorResource$Type at
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1305)
at
org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1139)
at
org.iotivity.simulator.agent.LaunchSimulator.doPost(LaunchSimulator.java:86)
at
org.iotivity.simulator.agent.LaunchSimulator.doGet(LaunchSimulator.java:45)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622) at
javax.servlet.http.HttpServlet.service(HttpServlet.java:729) at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:522)
at
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1095)
at
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672)
at
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1502)
at
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1458)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
I have tried the same code with a simple Java Application, and it works fine by setting the LD_LIBRARY_PATH variable.
Any suggestion will be highly appreciated.

Your error is a ClassNotFoundException, which would suggest that the JAR isn't properly included. If there was a problem with the native library, you'd get a UnsatisfiedLinkError instead. To make the JAR available to Tomcat, you'd need to add it to the classpath (-classpath=/path/to/your.jar) or include it in your WAR. The latter depends on your build system, but if you use Maven it's rather easy using the maven-shade-plugin (this only works for the JAR though, the native code you'll have to keep on distributing separately). Hope that helps!

Access encrypted database from H2 console

I want to store my H2 database as an encrypted file and access its web interface.
I configured H2 database so that I can access web interface to manipulate the database under console/db address.
When I do not use encryption everything works fine.
When I add CIPHER=AES to db.url I cannot log into the database and get below exception:
File corrupted while reading record: null. Possible solution: use the recovery tool [90030-191] 90030/90030 (Help)
org.h2.jdbc.JdbcSQLException: Uszkodzenie pliku podczas wczytywania rekordu: null
File corrupted while reading record: null. Possible solution: use the recovery tool [90030-191]
at org.h2.message.DbException.getJdbcSQLException(DbException.java:345)
at org.h2.message.DbException.get(DbException.java:168)
at org.h2.mvstore.db.MVTableEngine$Store.convertIllegalStateException(MVTableEngine.java:195)
at org.h2.mvstore.db.MVTableEngine$Store.open(MVTableEngine.java:167)
at org.h2.mvstore.db.MVTableEngine.init(MVTableEngine.java:99)
at org.h2.engine.Database.getPageStore(Database.java:2460)
at org.h2.engine.Database.open(Database.java:692)
at org.h2.engine.Database.openDatabase(Database.java:270)
at org.h2.engine.Database.<init>(Database.java:264)
at org.h2.engine.Engine.openSession(Engine.java:65)
at org.h2.engine.Engine.openSession(Engine.java:175)
at org.h2.engine.Engine.createSessionAndValidate(Engine.java:153)
at org.h2.engine.Engine.createSession(Engine.java:136)
at org.h2.engine.Engine.createSession(Engine.java:28)
at org.h2.engine.SessionRemote.connectEmbeddedOrServer(SessionRemote.java:349)
at org.h2.jdbc.JdbcConnection.<init>(JdbcConnection.java:107)
at org.h2.jdbc.JdbcConnection.<init>(JdbcConnection.java:91)
at org.h2.Driver.connect(Driver.java:72)
at org.h2.server.web.WebServer.getConnection(WebServer.java:735)
at org.h2.server.web.WebApp.login(WebApp.java:955)
at org.h2.server.web.WebApp.process(WebApp.java:211)
at org.h2.server.web.WebApp.processRequest(WebApp.java:170)
at org.h2.server.web.WebServlet.doGet(WebServlet.java:125)
at org.h2.server.web.WebServlet.doPost(WebServlet.java:162)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:121)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:522)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1095)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1502)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1458)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalStateException: Store header is corrupt: nio:/home/robak/db/adzfo.mv.db [1.4.191/6]
at org.h2.mvstore.DataUtils.newIllegalStateException(DataUtils.java:773)
at org.h2.mvstore.MVStore.readStoreHeader(MVStore.java:603)
at org.h2.mvstore.MVStore.<init>(MVStore.java:353)
at org.h2.mvstore.MVStore$Builder.open(MVStore.java:2888)
at org.h2.mvstore.db.MVTableEngine$Store.open(MVTableEngine.java:154)
... 47 more
Database Configuration
db.driver=org.h2.Driver
db.url=jdbc:h2:file:~/db/app_name;AUTO_SERVER=TRUE;CIPHER=AES
db.username=user
db.password=password
Servlet Context
private void configureDatabaseConsole(ServletContext servletContext) {
ServletRegistration.Dynamic h2Servlet = servletContext.addServlet("h2console", WebServlet.class);
h2Servlet.setLoadOnStartup(2);
h2Servlet.addMapping("/console/db/*");
}
Data source
#Bean
public DataSource dataSource() {
DriverManagerDataSource dataSource = new DriverManagerDataSource();
dataSource.setDriverClassName(getProperty(DRIVER));
dataSource.setUrl(getProperty(URL));
dataSource.setUsername(getProperty(USERNAME));
dataSource.setPassword(FILE_PASSWORD + " " + getProperty(PASSWORD));
return dataSource;
}
What should I do to have an encrypted database as a file on a hard drive and to access its console via web interface?

Are you sure you using the right password. Quoting from the H2 documentation File Encryption
The encryption algorithm is set in the database URL, and the file
password is specified in the password field, before the user
password. A single space separates the file password and the user
password; the file password itself may not contain spaces. File
passwords and user passwords are case sensitive. Here is an example
to connect to a password-encrypted database:
Class.forName("org.h2.Driver");
String url = "jdbc:h2:~/test;CIPHER=AES";
String user = "sa";
String pwds = "filepwd userpwd";
conn = DriverManager.
getConnection(url, user, pwds);
If you don't provide the correct password you won't get a connection.

java.lang.ClassNotFoundException while uploading an encrypted PDF file

I am getting the following exception when I am trying to upload a password protected PDF file in my application:
How to solve this problem? I tried different itext versions but still the same error. Is there anyway I can solve this issue? Thanks.
java.lang.ClassNotFoundException: org.bouncycastle.asn1.DEREncodable
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1358)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1204)
at com.itextpdf.text.pdf.PdfEncryption.<init>(PdfEncryption.java:138)
at com.itextpdf.text.pdf.PdfReader.readDecryptedDocObj(PdfReader.java:762)
at com.itextpdf.text.pdf.PdfReader.readDocObj(PdfReader.java:1133)
at com.itextpdf.text.pdf.PdfReader.readPdf(PdfReader.java:511)
at com.itextpdf.text.pdf.PdfReader.<init>(PdfReader.java:171)
at com.itextpdf.text.pdf.PdfReader.<init>(PdfReader.java:160)
at com.quepio.web.controller.TutoContentController.processChapterContent(TutoContentController.java:2582)
at com.quepio.web.controller.TutoContentController.saveOrUpdateContent(TutoContentController.java:1694)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:440)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:428)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:933)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:867)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:953)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:855)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:829)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:106)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.quepio.web.TwoFactorAuthenticationFilter.doFilterInternal(TwoFactorAuthenticationFilter.java:54)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:106)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.quepio.web.FirstLoginFilter.doFilterInternal(FirstLoginFilter.java:108)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:106)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
I am using the following jars.
itext: 5.3.2
bcprov-jdk15on: 1.47
bcmail-jdk15on: 1.47

You have to look at the POM file that ships with iText: pom.xml
You'll discover that the current version of iText is 5.5.7:
<artifactId>itextpdf</artifactId>
<packaging>jar</packaging>
<name>iText, a Free Java-PDF library</name>
<version>5.5.7</version>
<description>iText, a free Java-PDF library</description>
Now scroll down to the dependencies and look for BouncyCastle:
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcprov-jdk15on</artifactId>
<version>1.49</version>
<type>jar</type>
<scope>compile</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcpkix-jdk15on</artifactId>
<version>1.49</version>
<type>jar</type>
<scope>compile</scope>
<optional>true</optional>
</dependency>
As you can see, the BC version that works with 5.5.7 is BC 1.49.
The POM files are provided, so that developers don't have to resort to "trial and error." If you are familiar with Maven, just use the POM file and you don't have to worry about which BouncyCastle version to use. All the dependencies will be downloaded automatically through Maven.
Of course: you have to make sure that BC is also available in the CLASSPATH of your server. You also need to take special care to make sure that you have only one version of BouncyCastle. A ClassNotFoundException doesn't always mean that the class isn't present. It can also mean that there's an ambiguity. If you have a class named DEREncodable in one version of BC that is in your CLASSPATH and a class with the same name in another version of BC that is in your class path, the JVM won't know which class to use and will also throw a ClassNotFoundException.